17466( 6) - 18-Nov-2024 17:51:07 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17466 Version: 6 Check-in Time: 18-Nov-2024 17:51:07 STScI Edit Number: 2 Title Tracing the wobble: astrometric monitoring of the first Y+Y brown dwarf binary ------------------------------------------------------------------------------------ Type Cycle GO 31 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Clemence Fontanive Universite de Montreal Y CoI: Dr. Luigi R. Bedin INAF - Osservatorio Astronomico di Padova N CoI: Dr. Loic Albert Universite de Montreal N CoI: Dr. Matthew De Furio University of Texas at Austin N ------------------------------------------------------------------------------------ Abstract We propose a comprehensive astrometric follow-up of the first Y+Y brown dwarf binary, WISE 0336-0143 AB, a <1-AU separation and low mass ratio system detected with JWST. We aim to follow the ~50-mas astrometric wobble of the photocentre resulting from the binary orbital motion, by exploiting HST's high astrometric precision with WFC3/IR. Our program will accurately measure the system's proper motion, trigonometric parallax, and orbital configuration, at an unprecedented accuracy of <0.5 mas through asbolute astrometric calibrations using Gaia. Capitalising on the three archival HST epochs already available and the recent JWST results, we have a unique opportunity to simultaneously refine the system's distance and to measure the individual components' dynamical masses, by acquiring only four new HST epochs over the next two years. These additional carefully timed datasets are required to demarcate the absolute astrometric displacement of the barycentre and remaining on-sky offsets due to the orbital motion of the binary components around the centre of mass. This work will be crucial to anchor current and future observed characteristics of the unique WISE 0336-0143 benchmark, significantly contributing to our understanding of its fundamental and binary properties, and an important step forward in the characterisation and atmospheric modelling of Y-temperature giant exoplanets and brown dwarfs. In addition, this program will also pave the way for future investigations of sub-AU binary systems around faint Y dwarfs, and will provide us with an extensive dataset to develop a framework for joint astrometric analyses linking HST, JWST and Gaia data. ------------------------------------------------------------------------------------ Observations Description ------------------------ This multi-cycle program consists of 2 orbits of WFC3 IR channel imaging in Cycle 31 (and 2 more orbits in C32) for precise astrometric monitoring of a newly discovered Y+Y brown dwarf binary. All orbits are planned as single-orbit visits. We apply large and fractional-pixel dithering patterns to allow both removal of hot pixels and increase the spatial resolution of the datasets. All observations are taken in full frame mode, in order to maximise the number of reference sources in the fields of view. 17466( 6) - 18-Nov-2024 17:51:07 - [ 2] Following the strategy from GO 16229 for the same target, we will acquire 2 F105W exposures and a set of 6 F160W images. The F105W images will be placed in the middle of the sequences, to avoid problems associated with contaminating scattered Earthlight at low limb angles at those wavekengths. We will use 278 s exposures in MULTIACCUM mode, with suitable sampling times and sequence to maximise to total exposure times. We request specific time constraints for each visit, in order to optimise our science results in the derivation of the system's parallax, proper motion, and orbital motion. Based on phases of the year already covered by existing HST datasets for this system, and the allowed visibility windows in Cycle 31, we propose to obtain our 2 visits around early/mid Dec 2023 and late Jun/mid Aug 2024. With these new epochs, we will be able to start separating offsets from the barycentric motion from additional perturbations due to the binary, enabling the derivation of preliminary constraints for the orbit. We will then determine the optimal timing for the last two epochs in Cycle 32, based on remaining degeneracies in the derived solutions. ------------------------------------------------------------------------------------ 17466( 6) - 18-Nov-2024 17:51:07 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 WISE0336-014 STAR, BROWN DWARF RA=03H36M5.0062S, J2000 H=22 3 DEC=-01D43'55.80" Reference Frame: ICRS Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2014.0 -0.017194523746510478 -1.2123 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 17466( 6) - 18-Nov-2024 17:51:07 - [ 4] Visit: 01 Visit Requirements: BETWEEN 19-NOV-2023:00:00:00 AND 16-DEC-2023:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 WISE0336-01 WFC3/IR MULTIAC IR F160W NSAMP=12, SAMP-SEQ=SPARS25 1 DEF POS TARG 7.34, 7.30; SEQ 43 CUM (277.938 1-8 NON-INT S) ------------------------------------------------------------------------------------------------------------------------------------ 2 WISE0336-01 WFC3/IR MULTIAC IR F160W NSAMP=12, SAMP-SEQ=SPARS25 1 DEF POS TARG -5.34, -1.73 43 CUM (277.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WISE0336-01 WFC3/IR MULTIAC IR F160W NSAMP=12, SAMP-SEQ=SPARS25 1 DEF POS TARG -7.24, -7.16 43 CUM (277.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 WISE0336-01 WFC3/IR MULTIAC IR F105W NSAMP=12, SAMP-SEQ=SPARS25 1 DEF POS TARG 3.69, -3.57 43 CUM (277.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 WISE0336-01 WFC3/IR MULTIAC IR F105W NSAMP=12, SAMP-SEQ=SPARS25 1 DEF POS TARG -3.59, 3.65 43 CUM (277.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 WISE0336-01 WFC3/IR MULTIAC IR F160W NSAMP=12, SAMP-SEQ=SPARS25 1 DEF POS TARG -1.69, -5.45 43 CUM (277.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 WISE0336-01 WFC3/IR MULTIAC IR F160W NSAMP=12, SAMP-SEQ=SPARS25 1 DEF POS TARG 1.83, 5.50 43 CUM (277.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 8 WISE0336-01 WFC3/IR MULTIAC IR F160W NSAMP=11, SAMP-SEQ=SPARS25 1 DEF POS TARG 5.52, 1.89 43 CUM (252.937 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ WISE0336-0143 1 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM WISE0336-0143 2 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM 17466( 6) - 18-Nov-2024 17:51:07 - [ 5] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ WISE0336-0143 3 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM WISE0336-0143 4 WFC3/IR MULTIAC IR F105W none none none none 1 N/A CUM WISE0336-0143 5 WFC3/IR MULTIAC IR F105W none none none none 1 N/A CUM WISE0336-0143 6 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM WISE0336-0143 7 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM WISE0336-0143 8 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM 17466( 6) - 18-Nov-2024 17:51:07 - [ 6] Visit: 02 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 WISE0336-01 WFC3/IR MULTIAC IR F160W NSAMP=13, SAMP-SEQ=SPARS25 1 DEF POS TARG 7.34, 7.30; SEQ 43 CUM (302.938 1-7 NON-INT S) ------------------------------------------------------------------------------------------------------------------------------------ 2 WISE0336-01 WFC3/IR MULTIAC IR F160W NSAMP=13, SAMP-SEQ=SPARS25 1 DEF POS TARG -5.34, -1.73 43 CUM (302.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WISE0336-01 WFC3/IR MULTIAC IR F160W NSAMP=13, SAMP-SEQ=SPARS25 1 DEF POS TARG -7.24, -7.16 43 CUM (302.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 WISE0336-01 WFC3/IR MULTIAC IR F105W NSAMP=13, SAMP-SEQ=SPARS25 1 DEF POS TARG 3.69, -3.57 43 CUM (302.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 WISE0336-01 WFC3/IR MULTIAC IR F105W NSAMP=13, SAMP-SEQ=SPARS25 1 DEF POS TARG -3.59, 3.65 43 CUM (302.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 WISE0336-01 WFC3/IR MULTIAC IR F160W NSAMP=13, SAMP-SEQ=SPARS25 1 DEF POS TARG -1.69, -5.45 43 CUM (302.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 WISE0336-01 WFC3/IR MULTIAC IR F160W NSAMP=13, SAMP-SEQ=SPARS25 1 DEF POS TARG 1.83, 5.50 43 CUM (302.938 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ WISE0336-0143 1 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM WISE0336-0143 2 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM WISE0336-0143 3 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM WISE0336-0143 4 WFC3/IR MULTIAC IR F105W none none none none 1 N/A CUM 17466( 6) - 18-Nov-2024 17:51:07 - [ 7] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ WISE0336-0143 5 WFC3/IR MULTIAC IR F105W none none none none 1 N/A CUM WISE0336-0143 6 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM WISE0336-0143 7 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM 17466( 6) - 18-Nov-2024 17:51:07 - [ 8] Visit: 52 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 WISE0336-01 WFC3/IR MULTIAC IR F160W NSAMP=13, SAMP-SEQ=SPARS25 1 DEF POS TARG 7.34, 7.30; SEQ 43 CUM (302.938 1-7 NON-INT S) ------------------------------------------------------------------------------------------------------------------------------------ 2 WISE0336-01 WFC3/IR MULTIAC IR F160W NSAMP=13, SAMP-SEQ=SPARS25 1 DEF POS TARG -5.34, -1.73 43 CUM (302.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WISE0336-01 WFC3/IR MULTIAC IR F160W NSAMP=13, SAMP-SEQ=SPARS25 1 DEF POS TARG -7.24, -7.16 43 CUM (302.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 WISE0336-01 WFC3/IR MULTIAC IR F105W NSAMP=13, SAMP-SEQ=SPARS25 1 DEF POS TARG 3.69, -3.57 43 CUM (302.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 WISE0336-01 WFC3/IR MULTIAC IR F105W NSAMP=13, SAMP-SEQ=SPARS25 1 DEF POS TARG -3.59, 3.65 43 CUM (302.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 WISE0336-01 WFC3/IR MULTIAC IR F160W NSAMP=13, SAMP-SEQ=SPARS25 1 DEF POS TARG -1.69, -5.45 43 CUM (302.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 WISE0336-01 WFC3/IR MULTIAC IR F160W NSAMP=13, SAMP-SEQ=SPARS25 1 DEF POS TARG 1.83, 5.50 43 CUM (302.938 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ WISE0336-0143 1 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM WISE0336-0143 2 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM WISE0336-0143 3 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM WISE0336-0143 4 WFC3/IR MULTIAC IR F105W none none none none 1 N/A CUM 17466( 6) - 18-Nov-2024 17:51:07 - [ 9] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ WISE0336-0143 5 WFC3/IR MULTIAC IR F105W none none none none 1 N/A CUM WISE0336-0143 6 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM WISE0336-0143 7 WFC3/IR MULTIAC IR F160W none none none none 1 N/A CUM 17466( 6) - 18-Nov-2024 17:51:07 - [ 10] Summary Form for Proposal 17466 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NSAMP=11, NSAMP=12, NSAMP=13, SAMP-SEQ=SPARS25 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 19-NOV-2023:00:00:00 AND 16-DEC-2023:00:00:00, POS TARG -1.69, -5.45, POS TARG -3.59, 3.65, POS TARG -5.34, -1.73, POS TARG -7.24, -7.16, POS TARG 1.83, 5.50, POS TARG 3.69, -3.57, POS TARG 5.52, 1.89, POS TARG 7.34, 7.30, SEQ 1-7 NON-INT, SEQ 1-8 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F105W, F160W ------------------------------------------------------------------------------------------------------------------------------------ Target Names WISE0336-0143 ------------------------------------------------------------------------------------------------------------------------------------